Tag: Large Magellanic Cloud

In the heart of the Large Magellanic Cloud (one of the Milky Way’s many satellite galaxies), there lies a vast complex of gas called 30 Doradus. And inside that sprawling volume of space is the Tarantula Nebula, a star-forming region so huge it dwarfs even our own Orion Nebula. Thousands of stars are churning away in there, going through the process of being born.

And as they do, the hottest and brightest of them carve huge cavities in the nebula, heating the tenuous gas therein to millions of degrees. The result? This:

[Click to embiggen.]

I love this image! It’s a combination of observations from the Chandra X-Ray Observatory (in blue, showing the incredibly hot gas) and from Spitzer Space Telescope (in red, showing cooler gas). Those bubbles of hot, X-ray emitting gas are constrained by the cooler gas around them, but it’s likely the hot gas is expanding, driving the overall expansion of the nebula itself. However, it’s also possible the sheer flood of high-energy radiation from the nascent stars is behind the gas’s expansion… or it’s a combination of both. Astronomers are still arguing over this, and observations like this one will help figure out who’s right.

… but you know me. I love pareidolia, and there’s no way you can look at this image and not see a really angry screaming face, shrieking at that blue blob hovering in its way. That’s so cool!

And c’mon, NASA: you release this image two weeks after Halloween? Oh well, I’ll add it to my scary astronomy gallery anyway, which is after the jump below.

I love to post pretty pictures of galaxies and wax lyrical about their magnificent structure, complex history, and complicated internal compositions.

… and then there’s the Carina Dwarf galaxy. It’s so small and faint it wasn’t even discovered until 1977 even though it’s one of the closest galaxies in the sky! How did it avoid detection so long? This’ll make it obvious:

[Click to unendwarfenate.]

See it? Yeah, it’s that faint smattering of stars in the middle of the picture (the bright star near the center is in our Milky Way and coincidentally aligned with Carina). Not much to it, is there? It’s about 300,000 light years away, only 1/10th as far as the much brighter and more famous Andromeda Galaxy, and only about twice as distant as our two satellite galaxies, the Small and Large Magellanic Clouds, both of which are easily visible to the unaided eye.

Like the LMC and SMC, it is apparently a satellite of the Milky Way, but formed long after we did; studies of the stars in the Carina Dwarf indicate it’s only about 7 billion years old at most, while our galaxy is well over 10 billion years old. It probably formed from primordial gas orbiting the Milky Way, taking much longer due to its low mass and relatively quiet environment.

This image is a combination of observations taken with the 2.2 meter MPG/ESO and the Victor M. Blanco 4-meter telescopes in Chile. It shows that the galaxy has very little or no gas at all in it, and so its career in star-formation is long dead. But there’s still much to learn from such objects: they get eaten by bigger galaxies, for example. This cosmic cannibalism is one way galaxies like ours get so big, so studying these smaller bite-sized snacks in situ help us learn about ones we’ve already munched on.

Plus, galaxies like Carina might be the most common in the Universe! We just can’t see them because even at relatively small distances they fade away into the background. They may not be as flashy as spirals or as monstrous as giant elliptical galaxies, but they play an important role in building up such beasts. The more we know about them, the better we’ll understand the Universe itself.

What a breathtaking panorama! It’s dominated by the Milky Way Galaxy, hanging low near the horizon. We live inside the disk of our galaxy, so we see it from the inside out. It makes a thick line across the sky, the central hub bulging out in the middle. Dust chokes the interstellar view, creating dark lanes that block the light from stars behind them.

On the left you can see the two companion dwarf galaxies to our own: the Large and Small Magellanic Clouds. They apparently hang side-by-side in the sky, but are separated by over 40,000 light years… and are removed from us by distances of 160,000 and 200,000 light years, respectively.

And on the right is our eye on the sky, Unit Telescope 1 of the VLT — and that’s only one of four of the giant 8 meter telescopes in operation. I like the imagery here: the telescope at one end, distant galaxies on the other, and bridging them like a cosmic rainbow is our home galaxy itself.

You may make your own metaphor here, but the one I choose is obvious. You might even say this post is entitled to it.

[Edited to add: After writing this, but before posting it, I found that APOD had a very similar picture to this one. Funny coincidence!]

Over the past few months I’ve written about various nebulae that are busily forming stars. Orion is a great one, NGC 604 in the Triangulum Galaxy is another. But in nearby space, the great grand-daddy of them all is the vast, sprawling Tarantula Nebula. Located 170,000 light years away in the Large Magellanic Cloud — a satellite galaxy to our Milky Way — it is churning out stars at a mind-numbing rate. Astronomers pointed Hubble into its heart (it’s far too big to be seen all at once by Hubble) and got quite an eye full:

Holy Haleakala! That’s gorgeous!

[Click to arachnidate, or get the 3868 x 3952 pixel version. And yeah, you want a bigger one; I had to compress the picture to display it here, and the bigger ones are really something.]

This area is a mess. The gas and dust are obvious enough, as are the great number of stars littering that volume of space. Quite a few of the stars you see there are newborns. But note the tendrils and filaments of gas to the left of center, and to a lesser extent to the upper right. Those are the shock-wave compressed sheets of gas from a supernova, a star that exploded right in the center of all that. A massive star must have formed here, lived out its short life, and detonated. The debris expanded at thousands of kilometers per second, slamming into and compressing the gas. It wouldn’t surprise me if this expanding debris helped collapse more gas at its outer edges, helping more stars get born.

It’s the circle of life, or I guess, in this case, it’s the spherical shell of life.

To say this region is vast is seriously underestimating it. Astronomers are actually arguing not that it’s forming stars, but that it may be forming a nascent globular cluster, a collection of hundreds of thousands or even million of stars!

Mind you, the Tarantula is easily visible using just binoculars; I saw it myself when I visited Australia a few years ago. That flight to Oz was an uncomfortable 14 hours long, and I traveled about 12,000 kilometers. The light from the Tarantula had a bit of a tougher trip: it traveled 1,700,000,000,000,000,000 km to reach my eye, almost two quintillion kilometers!

Deep inside the Milky Way’s companion galaxy called the Large Magellanic Cloud lies a vast complex of stars, gas, and dust. From our vantage point, 170,000 light years away, we see it as a softly-glowing pinkish brain-shaped cloud studded with stars — a description that grossly underdescribes the tremendous beauty of the newly-released Hubble view of it:

Oh, my. Click it to get a bigger version, or go here to get a 26 Mb 4000×4000 pixel version.

What a staggeringly lovely image! And so much to see. More than you’d expect… but that’s part of a surprise I’ll have for you at the end of this post. Bear with me, it’s worth it.

I deal with superginormously ridiculous energies, velocities, and sizes all the time as an astronomer. You get used to it after a while… then something like this’ll slap you upside the head: a star that exploded more than 5000 years ago launched two epic bullets. One is a cloud of gas screaming away at thousands of kilometers per second, and the other is the cinder of the star itself, an octillion-ton cannonball blasting through space in a totally different direction.

This is a composite picture of the supernova remnant N49: an expanding lumpy sphere of gas about 30 light years across (300 trillion kilometers, or 180 trillion miles)*, located in the Large Magellanic Cloud, a satellite galaxy to our Milky Way. The blue in the picture is the emission from gas heated to millions of degrees, and shows X-rays detected by the Chandra observatory. The yellow and purple are from Hubble data, showing gas being whipped and beaten by shock waves slamming around insides the remnant.

Turn your attention to the little blue blob to the right, marked by the red arrow. It’s outside the main bubble of the nebula, meaning that it must be moving faster than the gas in general. This is seen sometimes in supernovae remnants: a bullet or focused blob of gas screaming away. It may be caused by magnetic fields in the expanding gas just after the star explodes, launching the octillions of tons of matter away in all directions, or it may be due to focusing from shock waves, which can sculpt the gas and create little pockets of denser knots.Read More

As someone who spends a lot of time thinking about astronomy and the weird stuff that happens on a daily basis in space, I see a lot of amazing things. You’d think I’d get used to the awesomeness of astronomy, but the opposite is true: I’m always spellbound by what I find.

Still, it takes a lot to seriously impress me, to really make me say Holy Frak.

Well, astronomers have just announced that they have found a massive star that has been flung out of the cluster in which it was born. The star is huge — 90 times the mass of the Sun — and is screaming away from its nursery at 400,000 kilometers per hour.

Holy Frak.

This incredible image is from the ESO’s 2.2 meter telescope in Chile. It shows an overview of the sprawling 30 Doradus star-forming cloud, located about 180,000 light years away in the satellite galaxy to the Milky Way called the Large Magellanic Cloud (or the LMC to those in the know). In the center of 30 Dor sits a vast cluster of stars called R136. The total combined mass of all the stars in R136 is unclear, but it has several that tip the cosmic scale at 100 times the mass of the Sun, which is the upper limit of how big a star can get without tearing itself apart.Read More